6.5 Grendel Compressed?

[goodlookin1]

Hey guys,

I tried signing up for the 65grendel forums but the administrator approval isnt going through, so here I am.

I just loaded up my first set of Grendel rounds. I am using CCI #450 primers, brand new Hornady brass, Ramshot (Western) Tac powder and Sierra MatchKing 107gr bullets. I am doing everything to spec as per AA guidelines. Their newest reloading data sheet says that the max load is 29.5 grains of Tac powder, but when I load that amount up, the bullet compresses the powder to where you cant shake the powder in the finished round at all.

I have to wonder, should I be concerned about this? The load specs dont list a minimum.....I was going to try and load it down a grain or two just to make sure it was safe, but I really only like following the manufacturers recommendations on loads until I am really comfortable and have tested everything out.

What would you guys do? Smart reloading techniques always say start with a minimum load and work up to the max. In this case, there IS no minimum load listed. Anyone loaded Grendel round with Tac powder before?

Thanks.

[762cavalier]

Ummm I would not run max loads unless I had worked up to them. It is always safe to reduce max loads by 10% for a starting load.

Now to answer your question. Compressed loads are not a problem. However they are not a problem only if you have worked up a safe load in YOUR rifle.

ETA Sorry I haven't had a chance to use TAC for my grendel yet. I am still using BLc-2. Although I have about 2 lbs of TAC to try at a later date.

[Sunwolf]

I notice compressed charges of VV N-135 at min. recommended loads using 7.62x39 brass necked down to .264..Min. load at 27.0 gr but had to go down to 24.5 to seat head.I guess the extra brass in the 7.62 has to go to the interior, reducing capacity somewhat.

[ar15barrels]

I just loaded up my first set of Grendel rounds.
I am doing everything to spec as per AA guidelines.
Their newest reloading data sheet says that the max load is 29.5 grains of Tac powder, but when I load that amount up, the bullet compresses the powder to where you cant shake the powder in the finished round at all.

While you may be following the published AA maximum, you are obviously NOT following the safe load development guidelines that are given in EVERY reloading manual.
If you had been, you would not be asking the question above.
Go read your reloading manual again and tell us what you are doing wrong.

Here's some incentive to follow the established safe methods that you are currently ignoring:

[goodlookin1]

I have not shot these rounds yet and am staying as safe as possible. Everything I have ever read about reloading says to ALWAYS stick to the specs. And that's what I did. I understand that I loaded those as the max listed, but I didnt have anything to start from. I have also read that too much empty case space can cause pressure spikes or overpressurized rounds in general, and can be unpredictable....so loading at 10% less capacity in my mind was an unknown and could lead to unintended consequences. I also looked at AA's other TAC loads like the 120 gr Berger: it is listed by AA as a starting load of 28.1 and a max load of 28.5.....that's only .4 gr difference! A simple 10% reduction from the max would put me at 2.5 gr less powder than the minimum listed specs. How am I supposed to know if a reduction in powder might have an opposite effect than what I intend (less pressure)?

AR15Barrels, I appreciate the sentiment.....and stated with such tact! Dont presume that I havent read my reloading books. I like my fingers, face, hands and arms just the way they are.....not lookin for a dirt nap. I studied and read a looong time before getting into reloading, ensuring all my ducks were in a row. I have been successfully reloading now for over a year (which in no way makes me even an expert), so it's not like i'm throwing my first ever load: I understand the procedures. Unfortunately, my book doesnt have the Grendel listed in it, and I couldnt find many sources for the reloading data with my powder. I'd rather not guess, so I figured this would be a good place to ask BEFORE shooting. In the mean time, since I already assembled the 10 rounds of the max 29.5 gr, I figured I'd set them aside until I could find the appropriate minimum load. IF it turned out that I could safely work up to them, then i'll shoot em. If not, i'll break them down and start over.

EDIT: BTW, yes....that picture is incentive. It confirmed my gut feeling to ask, verify, test and work up to the max before shooting.

[FLIGHT762]

"What would you guys do? Smart reloading techniques always say start with a minimum load and work up to the max."


What I would do is to start at 26.5 gr. and slowly work up to 29.5 looking for pressure signs.

In my 39 years of reloading, I've never started with a max recommended load. I have been surprised a few times when my rifle started showing excessive pressures before hitting the recommended max.

[ar15barrels]

I have not shot these rounds yet and am staying as safe as possible. Everything I have ever read about reloading says to ALWAYS stick to the specs. And that's what I did. I understand that I loaded those as the max listed, but I didnt have anything to start from. I have also read that too much empty case space can cause pressure spikes or overpressurized rounds in general, and can be unpredictable....so loading at 10% less capacity in my mind was an unknown and could lead to unintended consequences. I also looked at AA's other TAC loads like the 120 gr Berger: it is listed by AA as a starting load of 28.1 and a max load of 28.5.....that's only .4 gr difference! A simple 10% reduction from the max would put me at 2.5 gr less powder than the minimum listed specs. How am I supposed to know if a reduction in powder might have an opposite effect than what I intend (less pressure)?

AR15Barrels, I appreciate the sentiment.....and stated with such tact! Dont presume that I havent read my reloading books. I like my fingers, face, hands and arms just the way they are.....not lookin for a dirt nap. I studied and read a looong time before getting into reloading, ensuring all my ducks were in a row. I have been successfully reloading now for over a year (which in no way makes me even an expert), so it's not like i'm throwing my first ever load: I understand the procedures. Unfortunately, my book doesnt have the Grendel listed in it, and I couldnt find many sources for the reloading data with my powder. I'd rather not guess, so I figured this would be a good place to ask BEFORE shooting. In the mean time, since I already assembled the 10 rounds of the max 29.5 gr, I figured I'd set them aside until I could find the appropriate minimum load. IF it turned out that I could safely work up to them, then i'll shoot em. If not, i'll break them down and start over.

EDIT: BTW, yes....that picture is incentive. It confirmed my gut feeling to ask, verify, test and work up to the max before shooting.

Reading and comprehending are two very different things.

You are not going to run into pressure problems by reducing a max published load by 5%.
Many books will tell you to reduce max loads by 10% to start.
They will also caution you on some specific powders such as H110 and W296 as those should not be reduced much more than 5% from max.

AA's data is intrinsically flawed if they list a min/max powder charge range of just 0.4gr for the exact same bullet and the exact same powder at the exact same overall length.

[Rust]

start at 27 grains and work from there. It will be light but should still cycle fine. I've been getting some pretty nice groups (X<1")fireforming 7.62x39 with a load of 26 grains Tac and 120 Nos BT or SMK's

[goodlookin1]

start at 27 grains and work from there. It will be light but should still cycle fine. I've been getting some pretty nice groups (X<1")fireforming 7.62x39 with a load of 26 grains Tac and 120 Nos BT or SMK's

Have you found a significant pressure difference between the 7.62x39 large primer brass vs the Grendel small primer brass? That's one thing ive wondered about....Grendel brass is just ridiculously expensive. I've been thinking: Why not go 7.62x39 and neck it down? Any downsides besides extra work involved in fireforming and trimming?

[goodlookin1]

AA's data is intrinsically flawed if they list a min/max powder charge range of just 0.4gr for the exact same bullet and the exact same powder at the exact same overall length.

I wondered the same thing. Interestingly enough, other bullet loads they listed have almost a 2 gr spread.....then they had this 0.4 gr spread anomaly.

[Sunwolf]

Not much data out there for this cartridge.

[buffybuster]

Not too bad, little JB Weld and Alumahyde will fix that right up.

[TestPilot]

I ran the Grendel with 107 Sierra MK's thru QuickLoad for you...This data dependent on the case capacity, seating depth, case length and COAL specified below..If your are different this info WON'T APPLY...No warrantees/guarantees/liability for your use of this info...This if for info only and I don't recommend you load up anything in the RED and only work up to the purple loads with great care and caution looking for pressure signs.

Cartridge : 6.5 mm Grendel
Max Pressure: 52214-04.0 95 27.17 2600 1606 45719 5872 95.3 1.227 ! Near Maximum !
-03.0 96 27.45 2627 1639 47234 5929 95.7 1.210 ! Near Maximum !
-02.0 97 27.73 2653 1673 48813 5985 96.1 1.193 ! Near Maximum !
-01.0 98 28.02 2680 1706 50446 6039 96.4 1.177 ! Near Maximum !
+00.0 99 28.30 2706 1740 52140 6091 96.8 1.161 !DANGEROUS LOAD-DO NOT USE!
+01.0 100 28.58 2733 1774 53897 6141 97.1 1.145 !DANGEROUS LOAD-DO NOT USE!
+02.0 101 28.87 2759 1808 55715 6189 97.4 1.129 !DANGEROUS LOAD-DO NOT USE!
+03.0 102 29.15 2785 1843 57594 6235 97.7 1.114 !DANGEROUS LOAD-DO NOT USE!
+04.0 103 29.43 2812 1878 59538 6279 98.0 1.098 !DANGEROUS LOAD-DO NOT USE!
+05.0 104 29.72 2838 1914 61554 6321 98.2 1.083 !DANGEROUS LOAD-DO NOT USE!

[TestPilot]

Here's a look at other powders giving same Pressure/or 100% load density. Note that 50,000 PSI is the accepted Max P for the Grendel so these are a bit below that maximum...

Predicted Data for Indicated Charges of the Following Powders.
Matching Maximum Pressure: 45686 psi, or 315 MPa
or a maximum loading ratio or filling of 100 %These calculations refer to your specified settings in QuickLOAD 'Cartridge Dimensions' window.
C A U T I O N : any load listed can result in a powder charge that falls below minimum suggested
loads or exceeds maximum suggested loads as presented in current handloading manuals. Understand
that all of the listed powders can be unsuitable for the given combination of cartridge, bullet
and gun. Actual load order can vary, depending upon lot-to-lot powder and component variations.
USE ONLY FOR COMPARISON !

82 loads produced a Loading Ratio below user-defined minimum of 85%. These powders have been skipped.
Powder type Filling/Loading Ratio Charge Charge Vel. Prop.Burnt P max P muzz B_Time
% Grains Gramm fps % psi psi ms
--------------------------------- -----------------------------------------------------------------
Winchester WXR 100.0 26.4 1.71 1895 60.9 20354 4025 1.741
Winchester Supreme 780 100.0 28.1 1.82 2024 67.7 25643 4277 1.594
Winchester 760 100.0 28.2 1.83 2340 79.6 33619 5455 1.394
Winchester 748 96.9 27.8 1.80 2639 96.2 45687 6050 1.214 ! Near Maximum !

Vihtavuori N570 100.0 28.1 1.82 1635 40.2 16124 2896 1.951
Vihtavuori N560 100.0 27.2 1.77 1953 59.5 22331 4183 1.676
Vihtavuori N550 100.0 27.2 1.77 2301 82.8 30568 5457 1.441
Vihtavuori N540 100.0 26.9 1.75 2506 96.3 39968 5688 1.298
Vihtavuori N530 96.7 25.9 1.68 2586 95.3 45687 5788 1.231 ! Near Maximum !
Vihtavuori N32C Tin Star 85.2 11.3 0.73 1757 100.0 45687 1779 1.502 ! Near Maximum !
Vihtavuori N170 100.0 26.4 1.71 1615 46.8 15319 2921 1.988
Vihtavuori N165 100.0 26.4 1.71 1879 64.3 20891 3804 1.737
Vihtavuori N160 100.0 25.6 1.66 1918 64.7 22502 3798 1.668
Vihtavuori N150 100.0 25.2 1.63 2225 88.5 28922 4934 1.482
Vihtavuori N140 100.0 26.1 1.69 2491 97.0 40350 5417 1.295
Vihtavuori N135 100.0 24.2 1.57 2340 96.4 31868 5124 1.419
Vihtavuori N133 100.0 24.4 1.58 2484 99.2 42588 5023 1.275
Vihtavuori N130 96.0 23.9 1.55 2524 99.9 45687 5012 1.249 ! Near Maximum !
Vihtavuori N120 90.2 22.0 1.42 2493 100.0 45687 4469 1.253 ! Near Maximum !
Vihtavuori 24N41 100.0 28.4 1.84 1587 38.1 16374 2535 1.969
Vihtavuori 20N29 100.0 28.7 1.86 1338 29.9 11479 1878 2.307

Ramshot X-Terminator 88.9 25.4 1.64 2593 98.5 45687 5639 1.233 ! Near Maximum !
Ramshot TAC 95.2 27.2 1.76 2600 95.3 45687 5871 1.227 ! Near Maximum !
Ramshot Magnum (Big Boy) 100.0 28.5 1.85 1777 50.8 19683 3415 1.796
Ramshot Hunter 100.0 27.5 1.78 2195 76.5 28450 5048 1.493
Ramshot BigGame 100.0 27.5 1.78 2425 88.4 35871 5700 1.351

Norma URP 100.0 26.4 1.71 2217 80.5 28173 5148 1.491
Norma MRP 2 100.0 26.7 1.73 1706 50.1 16465 3299 1.914
Norma MRP 100.0 27.8 1.80 1984 63.9 22497 4471 1.664
Norma 204 100.0 27.5 1.78 2189 72.8 30191 4820 1.469
Norma 203B 100.0 26.7 1.73 2481 90.8 38189 5780 1.323
Norma 203 old 100.0 26.9 1.75 2413 90.5 34108 5697 1.384
Norma 202 100.0 26.2 1.70 2564 97.3 43135 5721 1.261
Norma 201 97.7 26.6 1.72 2580 95.2 45687 5805 1.249 ! Near Maximum !
Norma 200 85.3 23.5 1.52 2565 100.0 45687 5199 1.263 ! Near Maximum !

IMR 7828 SSC 100.0 27.4 1.77 1970 59.9 23872 4077 1.640
IMR 7828 100.0 25.9 1.68 1854 56.0 20396 3630 1.753
IMR 4895 100.0 26.7 1.73 2527 91.6 39821 5946 1.297
IMR 4831 100.0 25.5 1.65 2073 77.1 23605 4692 1.603
IMR 4350 100.0 26.5 1.72 2194 76.7 30212 4736 1.469
IMR 4320 100.0 26.2 1.70 2435 89.7 38359 5462 1.320
IMR 4198 92.1 22.0 1.43 2533 100.0 45687 4868 1.231 ! Near Maximum !
IMR 4064 100.0 25.2 1.63 2390 89.2 36879 5263 1.354
IMR 4007 SSC 100.0 27.0 1.75 2348 81.6 36903 5186 1.373
IMR 3031 100.0 24.9 1.61 2531 98.0 38359 5747 1.304

Hodgdon VARGET 100.0 25.8 1.67 2416 89.2 38157 5375 1.331
Hodgdon US 869 100.0 28.4 1.84 1458 34.1 13469 2199 2.142
Hodgdon Retumbo 100.0 26.8 1.74 1621 45.8 15484 2832 1.986
Hodgdon Hybrid 100V 100.0 24.9 1.61 2052 78.9 23841 4512 1.601
Hodgdon H870 100.0 27.5 1.78 1499 37.2 13454 2441 2.117
Hodgdon H4895 100.0 26.7 1.73 2594 94.0 44771 5965 1.242 ! Near Maximum !
Hodgdon H4831 SC 100.0 26.9 1.75 1994 63.8 24829 4099 1.617
Hodgdon H4831 100.0 25.9 1.68 1909 61.3 22177 3814 1.696
Hodgdon H4350 100.0 26.1 1.69 2149 75.3 28631 4598 1.502
Hodgdon H4198 88.4 22.1 1.43 2491 98.3 45687 4938 1.245 ! Near Maximum !
Hodgdon H414 100.0 28.2 1.83 2340 79.6 33619 5455 1.394
Hodgdon H380 100.0 27.2 1.77 2422 86.8 36858 5590 1.352
Hodgdon H335 91.6 26.7 1.73 2609 97.8 45687 5797 1.224 ! Near Maximum !
Hodgdon H322 96.9 25.1 1.62 2606 98.7 45687 5650 1.221 ! Near Maximum !
Hodgdon H1000 100.0 26.4 1.71 1697 49.0 17788 2964 1.881
Hodgdon Benchmark 96.4 25.3 1.64 2530 95.8 45687 5410 1.246 ! Near Maximum !
Hodgdon BL-C2 99.9 29.1 1.88 2643 95.0 45687 6209 1.218 ! Near Maximum !
Hodgdon 50BMG 100.0 27.1 1.75 1481 33.5 13740 2259 2.113

Alliant Reloder-50 100.0 28.8 1.87 1390 31.1 11686 2160 2.258
Alliant Reloder-25 100.0 26.5 1.72 1815 57.9 18762 3646 1.812
Alliant Reloder-22 100.0 26.9 1.75 1951 62.8 21850 4243 1.688
Alliant Reloder-19 100.0 26.7 1.73 2074 69.1 25688 4518 1.566
Alliant Reloder-17 100.0 28.0 1.81 2462 87.9 38699 5812 1.311
Alliant Reloder-15 100.0 26.7 1.73 2492 90.2 39061 5790 1.312
Alliant Reloder-12 96.3 26.2 1.70 2574 98.6 45687 5494 1.231 ! Near Maximum !
Alliant Reloder-10x 93.9 23.6 1.53 2581 100.0 45687 5337 1.243 ! Near Maximum !
Alliant Reloder- 7 87.1 22.5 1.46 2520 100.0 45687 4937 1.256 ! Near Maximum !

Accurate MAGPRO 100.0 28.3 1.84 1887 55.3 21095 3957 1.722
Accurate 8700 100.0 27.3 1.77 1354 31.9 11747 1869 2.285
Accurate 4350 100.0 25.5 1.65 2060 75.8 22411 4787 1.645
Accurate 4064 100.0 24.9 1.61 2309 93.1 29309 5439 1.502
Accurate 3100 100.0 25.2 1.63 1749 62.6 16198 3667 1.906
Accurate 2700 100.0 27.5 1.78 2282 80.6 36172 4793 1.396
Accurate 2520 100.0 27.5 1.78 2559 96.1 41175 5858 1.282
Accurate 2495 100.0 25.2 1.63 2491 98.4 36436 5744 1.377
Accurate 2460 95.4 27.3 1.77 2583 96.3 45687 5726 1.249 ! Near Maximum !
Accurate 2230 93.4 26.7 1.73 2567 96.2 45687 5606 1.247 ! Near Maximum !
Accurate 2200 88.0 23.8 1.54 2531 97.0 45687 5332 1.244 ! Near Maximum !
Accurate 2015 96.0 24.8 1.60 2570 99.8 45687 5317 1.249 ! Near Maximum !

[Rust]

Have you found a significant pressure difference between the 7.62x39 large primer brass vs the Grendel small primer brass? That's one thing ive wondered about....Grendel brass is just ridiculously expensive. I've been thinking: Why not go 7.62x39 and neck it down? Any downsides besides extra work involved in fireforming and trimming?

No, but I load the 7.62x39 light intentionally. I don't have the numbers on hand but 7.62x39 brass seems to vary quite a bit in terms of capacity so it's really important to look up what the volume of the brass you're using is. Or better yet weigh it with water yourself to check it out. Some of it will be (thick walled IMI IE) a couple grains lower in capacity.

As far as extra work I have not had to do anything extra yet, my fireforming loads are surprisingly accurate shooting quality bullets. And feed and cycle the rifle fine out of my mags. (Many people have not been so lucky with C-Products) The fireformed brass comes out a little shorter so it doesn't need to be trimmed. But some people have raised concerns about it forming a "doughnut" which should be reamed out. I personally have not seen it in my brass yet, but I have only done a couple of reloading each so far on my fireformed brass. I suppose it may develop as the brass flows forward under repeated firings.

Also in regards to Quickload and the Grendel. A lot of people have found that the data generated by Quickload shows pressures much higher than the testing done with actual ammo. For instance the data posted here shows 25.3 grains benchmark to produce 45k psi while Hogdons data shows 26 grains to produce 35k (their starting load for that powder).
or IMR 4198 listed at 22 grains producing 45k on quickload and Hogdon showing 21.5 grains producing 34k as a starting load.